1. Field of the Invention
The present invention relates to a disk player with disk changer functions, and more particularly to a drive mechanism or relative elevation of a disk-storage means in the disk player.
2. Description of the Prior Art
A disk player with disk changer functions is well known. The disk player of this type typically includes a removable stacker or magazine for storing a plurality of disks. In a position of the stacker installed in the disk player, a desired one of disks stored in the stacker may be transported to a disk-reading position in opposition to a disk-reading device.
Another type disk player with disk changer functions is disclosed in a co-pending application Ser. No. 07/572,050, filed Aug. 23, 1990, which comprises a nondetachable stacker for receiving a plurality of disks in a concentric array, a plurality of subframes each adapted to receive a disk and a single main frames adapted to receive one of the subframes. The main frame is movable between a disk-reading position inside the player and a disk-inserting/removing position outside the player. When the main frame stands in the disk-inserting/removing position, a disk may be inserted into or removed from the subframe received therein. This player allows a new disk to be read without necessity of removing the stacker.
In the conventional and above-referred updated disk player with disk changer functions, the stacker is mounted elevatably with respect to a disk-reading device for playback of the disk located in the disk-reading position, so that one of stairs in the stacker may be selected for playback or storage of the disk.
Japanese patent publication No. 124,154/1989 and No. 103,466/1988 disclose a similar arrangement of a mechanism for elevation of the disk-reading device relative to the stacker. In the mechanism disclosed, there is provided a plurality of cylindrical cams which are rotated by a drive gear mounted on a chassis, to move up and down the disk-reading device in engagement with elements thereof. This arrangement of the prior art mechanism requires that the cylindrical cams and the elements should be mounted at opposite sides of the disk-reading device, resulting in its dimension being considerably wider than the disk-reading device. This makes it difficult to minimize the overall size of the player. Further, it is not desirable to move the disk-reading device relative to a stationary stacker, since expected read-out of the disk would be affected due to a mechanically unavoidable instability of the mechanism for elevation of the disk-reading device.
The mechanism for relative movement of the stacker should meet a requirement that every stair in the stacker may be positioned just in flush with the plane of the disk located in the disk-reading position, to thereby ascertain smooth insertion of a new disk into a desired stair in the stacker or removal of a disused disk from a selective one of the stairs in the stacker. This is contemplated in one of the above-referred prior arts, Japanese patent publication No. 103,466/1988. More particularly, each cylindrical cam 16 has a plurality of unpitched screw sections 16b, one of which is adapted to engage, in every rotation of the cam, with the element 19 over a certain angular range of rotation. The stacker is to be stopped when the element 19 remains in one of the unpitched screw section 16b of the cylindrical cam 16. With this arrangement every stair in the stacker can surely be stopped in flush with the plane of the disk, even when an actual angular position in rotation of the cylindrical cams 16 should be somewhat offset due to poor accuracy in working of the drive gear 17, for example. However, in fact, manufacture of the cylindrical cams having such unique unpitched sections will be very difficult, which inevitably increase the overall costs of manufacture of the player.